code: def test_polynomial_encoder_2cols(self):
      train = [["A", "A"], ["B", "B"], ["C", "C"]]
  
      encoder = encoders.PolynomialEncoder(
          handle_unknown="value", handle_missing="value"
      )
      encoder.fit(train)
      obtained = encoder.transform(train)
  
      expected = [
          [
              1,
              a_encoding[1],
              a_encoding[2],
              a_encoding[1],
              a_encoding[2],
          ],
          [
              1,
              b_encoding[1],
              b_encoding[2],
              b_encoding[1],
              b_encoding[2],
          ],
          [
              1,
              c_encoding[1],
              c_encoding[2],
              c_encoding[1],
              c_encoding[2],
          ],
      ]
      self.assertEqual(
          deep_round(obtained.to_numpy().tolist()), deep_round(expected)
      )
  
file_path: category_encoders/tests/test_polynomial.py
imports: import pandas
  from unittest import TestCase
  import numpy
  import category_encoders
  from tests.helpers import deep_round
label_desc: Use image node_id 5 for calling the TestPolynomialEncoder obj's underlying member method code with example usage: obj.test_polynomial_encoder_2cols() without return types